| |
Records |
Links |
|
Author |
Sanchis-Lozano, M.A.; Melia, F.; Lopez-Corredoira, M.; Sanchis-Gual, N. |
|
| |
Title  |
Missing large-angle correlations versus even-odd point-parity imbalance in the cosmic microwave background |
Type |
Journal Article |
| |
Year |
2022 |
Publication |
Astronomy & Astrophysics |
Abbreviated Journal |
Astron. Astrophys. |
|
| |
Volume |
660 |
Issue |
|
Pages |
A121 - 10pp |
|
| |
Keywords |
cosmological parameters; cosmic background radiation; cosmology: observations; cosmology: theory; inflation; large-scale structure of Universe |
|
| |
Abstract |
Context. The existence of a maximum correlation angle (theta(max) & 60 greater than or similar to degrees) in the two-point angular temperature correlations of cosmic microwave background (CMB) radiation, measured by WMAP and Planck, stands in sharp contrast to the prediction of standard inflationary cosmology, in which the correlations should extend across the full sky (i.e., 180 degrees). The introduction of a hard lower cuto ff (k(min)) in the primordial power spectrum, however, leads naturally to the existence of theta(max). Among other cosmological anomalies detected in these data, an apparent dominance of odd-over-even parity multipoles has been seen in the angular power spectrum of the CMB. This feature, however, may simply be due to observational contamination in certain regions of the sky. Aims. In attempting to provide a more detailed assessment of whether this odd-over-even asymmetry is intrinsic to the CMB, we therefore proceed in this paper, first, to examine whether this odd-even parity imbalance also manifests itself in the angular correlation function and, second, to examine in detail the interplay between the presence of theta(max) and this observed anomaly. Methods. We employed several parity statistics and recalculated the angular correlation function for di fferent values of the cuto ff kmin in order to optimize the fit to the di fferent Planck 2018 data. Results. We find a phenomenological connection between these features in the data, concluding that both must be considered together in order to optimize the theoretical fit to the Planck 2018 data. Conclusions. This outcome is independent of whether the parity imbalance is intrinsic to the CMB, but if it is, the odd-over-even asymmetry would clearly point to the emergence of new physics. |
|
| |
Address |
[Sanchis-Lozano, M-A] Ctr Mixto Univ Valencia, Inst Fis Corpuscular IFIC, CSIC, Dr Moliner 50, Burjassot, Spain, Email: Miguel.Angel.Sanchis@ific.uv.es; |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Edp Sciences S A |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0004-6361 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000786712000002 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
5211 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Villaescusa-Navarro, F.; Vogelsberger, M.; Viel, M.; Loeb, A. |
|
| |
Title |
Neutrino signatures on the high-transmission regions of the Lyman alpha forest |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
|
| |
Volume |
431 |
Issue |
4 |
Pages |
3670-3677 |
|
| |
Keywords |
neutrinos; intergalactic medium; quasars: absorption lines; cosmology: theory; large-scale structure of Universe |
|
| |
Abstract |
We quantify the impact of massive neutrinos on the statistics of low-density regions in the intergalactic medium as probed by the Lyman alpha forest at redshifts z = 2.2-4. Based on mock but realistic quasar (QSO) spectra extracted from hydrodynamic simulations with cold dark matter, baryons and neutrinos, we find that the probability distribution of weak Lyman alpha absorption features, as sampled by Lyman alpha flux regions at high transmissivity, is strongly affected by the presence of massive neutrinos. We show that systematic errors affecting the Lyman alpha forest reduce but do not erase the neutrino signal. Using the Fisher matrix formalism, we conclude that the sum of the neutrino masses can be measured, using the method proposed in this paper, with a precision smaller than 0.4 eV using a catalogue of 200 high-resolution (signal-to-noise ratio similar to 100) QSO spectra. This number reduces to 0.27 eV by making use of reasonable priors in the other parameters that also affect the statistics of the high-transitivity regions of the Lyman alpha forest. The constraints obtained with this method can be combined with independent bounds from the cosmic microwave background, large-scale structures and measurements of the matter power spectrum from the Lyman alpha forest to produce tighter upper limits on the sum of the masses of the neutrinos. |
|
| |
Address |
Univ Valencia, IFIC, CSIC, E-46071 Valencia, Spain, Email: viel@oats.inaf.it |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Oxford Univ Press |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0035-8711 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000319479000057 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
1458 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Villanueva-Domingo, P.; Gnedin, N.Y.; Mena, O. |
|
| |
Title |
Warm Dark Matter and Cosmic Reionization |
Type |
Journal Article |
| |
Year |
2018 |
Publication |
Astrophysical Journal |
Abbreviated Journal |
Astrophys. J. |
|
| |
Volume |
852 |
Issue |
2 |
Pages |
139 - 7pp |
|
| |
Keywords |
cosmology: theory; galaxies: formation; intergalactic medium; large-scale structure of universe; methods: numerical |
|
| |
Abstract |
In models with dark matter made of particles with keV masses, such as a sterile neutrino, small-scale density perturbations are suppressed, delaying the period at which the lowest mass galaxies are formed and therefore shifting the reionization processes to later epochs. In this study, focusing on Warm Dark Matter (WDM) with masses close to its present lower bound, i.e., around the 3. keV region, we derive constraints from galaxy luminosity functions, the ionization history and the Gunn-Peterson effect. We show that even if star formation efficiency in the simulations is adjusted to match the observed UV galaxy luminosity functions in both CDM and WDM models, the full distribution of Gunn-Peterson optical depth retains the strong signature of delayed reionization in the WDM model. However, until the star formation and stellar feedback model used in modern galaxy formation simulations is constrained better, any conclusions on the nature of dark matter derived from reionization observables remain model-dependent. |
|
| |
Address |
[Villanueva-Domingo, Pablo; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain, Email: gnedin@fnal.gov |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0004-637x |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
WOS:000422865600009 |
Approved |
no |
|
| |
Is ISI |
yes |
International Collaboration |
yes |
|
| |
Call Number |
IFIC @ pastor @ |
Serial |
3455 |
|
| Permanent link to this record |
